Hydropower Net Head & Power Calculator

Switch units, enter values and the results update automatically. Use “Share link” to send the same inputs/results to anyone.

Inputs

Levels & Flow
m
Water surface elevation of the reservoir.
m
Average water level at the outlet / tailrace.
m³/s
Design discharge through the turbine(s).
%
Typical range: 85–95% (depends on turbine type and head).
%
Typical range: 95–99%.
Headlosses
m
%
Enter length OR percent (the other field clears automatically).
m
%
Enter length OR percent (the other field clears automatically).
m
%
Enter length OR percent (the other field clears automatically).

Assumptions: density ρ = 1000 kg/m³, gravity g = 9.81 m/s².

Results

Updates automatically
Site schematic
Not to scale
Reservoir RL: – Tailwater TL: – Turbine Hg: – Hnet: – Q: – Loss: –
Gross head is the elevation difference. Net head is gross head minus hydraulic losses.
Gross head (Reservoir − Tailwater)
– m
Total headloss (All components)
– m (– %)
Net head (Hnet)
– m
Combined efficiency (ηt × ηg)
– %
Hydraulic power (Phyd)
– kW (– MW)
Electrical power (Pel)
– kW (– MW)

Sample values are loaded. Edit any input to recalculate automatically.

Hydraulic power is the theoretical power available in the water at the net head (based on ρ·g·Q·Hnet). Electrical power is lower because it accounts for turbine and generator losses: Pel = Phyd × (ηt × ηg).